Comfortable orthopedic chair for prevention of spinal diseases

ABSTRACT

A chair comprises a seat and a seat back made of non-resilient materials. 
     The seat has a shape that matches the natural contours of an occupant&#39;s buttocks, thighs, and upper legs, wherein: The seat&#39;s concave backward portion connects to the concave lowest portion of the said seat back, creating a dedicated concave zone that contours the occupant&#39;s buttocks closely; the seat&#39;s concave backward portion has in its center a small hump that contours tightly an occupant&#39;s sacrum and coccyx if his buttocks are fitting inside the dedicated concave zone; the seat&#39;s forward portion has a wide W-shape that contours the occupant&#39;s upper legs: the two concave zones of the seat&#39;s W-shaped forward portion contours the back sides of the occupant&#39;s upper legs, the center zone of the seat&#39;s W-shaped forward portion is convex and snuggles the occupant&#39;s thighs; the left side and right side of the seat&#39;s W-shaped forward portion are convex so that they contour the outer sides of the occupant&#39;s upper legs; the seat is inclined backwardly. 
     The seat back tilts backward to stay at an angle of 135 degrees to the seat and contours the occupant&#39;s back, wherein: The seat back&#39;s lowest portion is concave to contour the occupant&#39;s buttocks; the middle portion that is convex to contour the lumbar vertebrae; the upper portion that is concave to contour the thoracic vertebrae; the top is a headrest to provide support to the occupant&#39;s head; the left and right edges of the seat back are convex so that the occupant&#39;s back cannot bend left or right.

RELATED APPLICATIONS

This application is a continuation-in-part of application No. PCT/IB2011/053859 filed on 03 Sep. 2011 with WIPO and application No. 13262636 filed on 2 Oct. 2011 with USPTO. The two applications have the same content.

FIELD OF THE INVENTION

The present invention generally relates to a chair, and in particular, to an orthopedic chair that is comfortable to use while being able to prevent spinal diseases including lumbar kyphosis, thoracic kyphosis, sacrum and coccyx misalignment, and herniated disc.

BACKGROUND OF THE INVENTION

Data from the British Chiropractic Association says that 32% of the population spends more than 10 hours a day seated. Together with the long working hour, incorrect seating postures lead to serious spinal diseases. Another research from the association shows that 51% of Brits suffer from some form of back pain. Given that, the role of correct seating positions cannot be clearer; it prevents spinal diseases and reduces back pain.

On Nov. 28, 2006, BBC News published an article named “Sitting straight bad for backs”. In which, it featured a research done by a group of Scottish and Canadian researchers confirming that the best sitting position is leaning back, whereas the upper legs are at an angle of 135 degrees to the spine. With the 135-degree sitting posture, less strain is placed on the spinal discs and associated muscles and tendons, compared to the strain in an upright 90-degree sitting position and in a slouching position where the body bends forward. When strain is placed on the spine, the spinal discs start to move and misalign. At a 90-degree sitting position, this movement is most prominent. The discs is least moved when an occupant is sitting back at a 135-degree sitting position. Therefore, sitting at 135-degree position can prevent spinal diseases.

Although a 135-degree chair offers the best sitting position, it actually requires a dedicated design to be comfortable to sit on. It has been found that maintaining substantially equal pressure distribution throughout the surface area of the body that is in contact with the chair results in the greater comfort.

Many chairs that are capable of offering a 135-degree sitting posture have been invented. U.S. Pat. No. 5,630,648 describes a chair with an adjustable seat back so that an occupant can achieve a 135-degree sitting posture. However, sitting on this chair, the occupant's buttocks tend to glide forwardly, making the occupant have to put his feet on the ground at all time to bear the gravity of his body to keep his buttocks in place. Given that, it is not comfortable to sit on the chair.

Tilt Seat™ Eco chair is another invention, in which the seat is tilted forwardly so that an occupant can obtain a 135-degree sitting posture. However, since the chair does not have a seat back, the occupant actually tends to bend forward, potentially leading to spinal diseases such as herniated discs.

SUMMARY OF THE INVENTION

The present invention provides an orthopedic chair that is comfortable to sit on and is able to prevent spinal diseases. The said orthopedic chair comprises an ergonomic seat and an ergonomic seat back. The said seat is mounted on a support that can include well-known height adjustment means; the support will not be described herein as it is not included in the invention.

The said seat is made of non-resilient materials and has a shape that matches the natural contours of an occupant's buttocks, thighs, and upper legs. In which, the said seat has its concave backward portion connect to the concave lowest portion of the said seat back, creating a dedicated concave zone that contours the occupant's buttocks closely but comfortably. In the center of the seat's concave backward portion is a small hump that contours tightly the occupant's sacrum and coccyx if his buttocks are fitting inside the dedicated concave zone.

The forward portion of the said seat has a wide W-shape that contours the occupant's upper legs comfortably. In which, the two concave zones of the seat's W-shaped forward portion contours the back sides of the occupant's upper legs. The center zone of the seat's W-shaped forward portion is convex and has two functions. The first function is to prevent the occupant's buttocks from gliding off the seat, keeping the buttocks stay in the dedicated concave zone. The second function is to encourage the occupant to fit his buttocks inside the dedicated concave zone, as sitting on the convex center zone of the

W-shaped forward portion is not comfortable.

Furthermore, to ensure that the occupant always fit his buttocks inside the dedicated concave zone, the seat is designed to be inclined backwardly in such a way that, when the occupant intentionally sits on the seat's W-shaped forward portion, his buttocks, pushed by the gravity force of his body, will gradually glide backward and fit themselves into the said dedicated concave zone eventually.

The left side and right side of the seat's W-shaped forward portion are convex so that they contour the outer sides of the occupant's upper legs. Moreover, the convex left and right sides of the seat's forward portion keep the upper legs in a correct position, i.e. inside the two concave zones of the seat's W-shaped forward portion, since putting the legs on top of the two convex left and right sides is not comfortable.

The said seat back is also made of non-resilient materials and is ergonomically designed in such a way that it contours the occupant's back. The seat back tilts backward to stay at an angle of 135 degrees to the seat.

The said seat back comprises a lowest portion, as already described above, that is concave to contour the occupant's buttocks, a middle portion that is convex to contour the lumbar vertebrae, an upper portion that is concave to contour the thoracic vertebrae, and a headrest on the top. The left and right edges of the seat back are convex to keep the occupant's back from bending left or right.

Here, a proper sitting posture is defined as a posture in which the occupant sits on the seat of the said chair in such a way that his buttocks fit inside the dedicated concave zone, his sacrum and coccyx are contoured tightly by the small hump in the center of the seat's concave backward portion, his two upper legs fit inside the two concave zones of the seat's W-shaped forward portion, and his back stays at an angle of 135 degrees to his upper legs and is contoured comfortably by the seat back. When an occupant is sitting in this proper sitting position, less strain is placed on the spinal disks and associated muscles and tendons. Given that the seat and the seat back are ergonomically designed and are made of non-resilient materials, the chair help the occupant easily and comfortably maintain an angle of 135 degrees between his back and upper legs over time; in other words, the pelvis stays at an “neutral” position and the shape of the spine is close to the natural S-shape in a standing posture. Since the chair keeps an occupant in a proper sitting posture, it is capable of preventing spinal diseases.

Moreover, as it is designed ergonomically to contour the occupant's body, the chair maintains substantially equal pressure distribution throughout the surface area of the body that is in contact with the chair, resulting that the occupant feels very comfortable sitting on the chair.

The brief description above sets forth rather broadly the more important features of the present invention in order that the detailed description thereof that follows may be better understood, and in order that the present contributions to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will be for the subject matter of the claims appended hereto. Before explaining the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception, upon which disclosure is based, may readily be utilized as a basis for designing other structures, methods, and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:

FIG. 1 is a perspective right-front view of a comfortable orthopedic chair for prevention of spinal disease according to the invention.

FIG. 2 is a perspective left-front view of the chair shown in FIG. 1

FIG. 3 is the same presentation as in FIG. 1 but with reference numbers.

FIG. 4 is the front view of the chair shown in FIG. 1

FIG. 5 is a left view of the chair shown in FIG. 1.

FIG. 6 is a cross-section front view of the seat of the chair shown in FIG. 5 taken along lines A-A

FIG. 7 is a cross-section front view of the seat of the chair shown in FIG. 5 taken along lines B-B

FIG. 8 is a cross-section top view of the back seat of the chair shown in FIG. 5 taken along lines C-C

FIG. 9 is a cross-section top view of the back seat of the chair shown in FIG. 5 taken along lines D-D

FIG. 10 is a cross-section top view of the back seat of the chair shown in FIG. 5 taken along lines E-E

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides an orthopedic chair that is comfortable to sit on and is able to prevent spinal diseases. Referring to FIG. 1, the said chair 100 comprises a seat 200 and a seat back 300. The said seat 200 is mounted on a support that can include well-known height adjustment means; the support will not be described herein as it is not included in the invention.

The said seat 200 is made of non-resilient materials and has a shape that matches the natural contours of an occupant's buttocks, thighs, and upper legs. In which, the said seat has its concave backward portion, consisting of concave zone 205 a and concave zone 205 b, connect to the concave lowest portion 302 of the said seat back 300, creating a dedicated concave zone 400 as circled in FIG. 3. The dedicated concave zone 400 contours the occupant's buttocks closely but comfortably. In the center of the seat's concave backward portion, i.e. between concave zone 205 a and concave zone 205 b, is a small hump 206 that fits tightly into the occupant's sacrum and coccyx if his buttocks is fitting inside the dedicated concave zone 400.

The forward portion of the said seat 200 has a wide W-shape that contours the occupant's upper legs comfortably. In which, the two concave zones 202 a and 202 b of the seat's W-shaped forward portion contour the back of the occupant's upper legs. The center zone 204 of the seat's W-shaped forward portion, i.e. between the two concave zones 202 a and 202 b, is convex and has two functions. The first function is to snuggle the occupant's thighs comfortably. The second function is to encourage the occupant to fit his buttocks inside the dedicated concave zone 400, as sitting on the convex center zone 204 is not comfortable.

Furthermore, to ensure that the occupant always fit his buttocks inside the dedicated concave zone 400 while seated, the seat 200 is designed to be inclined backwardly in such a way that, when the occupant intentionally sits on the forward portion of the seat 200, his buttocks, pushed by the gravity force of his body, will gradually glide backward and fit themselves into the dedicated concave zone 400 eventually.

The left side 203 a and the right side 203 b of the W-shaped forward portion of the seat 200 are convex so that they contour the outer sides of the occupant's upper legs. Moreover, the left side 203 a and the right side 203 b encourage the occupant keeps his upper legs in a correct position, i.e. inside the concave zones 202 a and 202 b, since putting the upper legs on top of the two convex sides 203 a and 203 b is not comfortable.

The said seat back 300 is also made of non-resilient materials and ergonomically designed in such a way that it contours the occupant's back comfortably. The seat back tilts backward to stay at an angle of 135 degrees to the seat, as shown in FIG. 5 The seat back 300 comprises a lowest portion 302, as already described above, that is concave to contour the occupant's buttocks, a middle portion 303 that is convex to contour the lumbar vertebrae, an upper portion 305 that is concave to contour the thoracic vertebrae, and a headrest 306 on the top. The left edge 304 a and right edge 304 b of the seat back 300 are convex to keep the occupant's back from bending left or right.

Here, a proper sitting posture is defined as a posture in which the occupant sits on the seat 200 of the said chair 100 in such a way that his buttocks fit inside the dedicated concave zone 400, his sacrum and coccyx are contoured tightly by the small hump 206, his two upper legs fit inside the two concave zones 202 a and 202 b of the seat's W-shaped forward portion, and his back stays at an angle of 135 degrees to his legs and is contoured comfortably by the seat back 300. When an occupant is sitting in this proper sitting position, less strain is placed on the spinal disks and associated muscles and tendons. Since the chair 100 keeps an occupant in a proper sitting posture, it is capable of preventing spinal diseases. As it is designed ergonomically to contour the occupant's body, the chair 100 maintains substantially equal pressure distribution throughout the surface area of the body that is in contact with the chair, resulting that the occupants feels very comfortable sitting on the chair. 

What is claimed is:
 1. A chair comprises a seat and a seat back made of non-resilient materials, in which: The seat has a shape that matches the natural contours of an occupant's buttocks, thighs, and upper legs, wherein: The seat's concave backward portion connects to the concave lowest portion of the said seat back, creating a dedicated concave zone that contours the occupant's buttocks closely; the seat's concave backward portion has in its center a small hump that contours tightly an occupant's sacrum and coccyx if his buttocks are fitting inside the dedicated concave zone; the seat's forward portion has a wide W-shape that contours the occupant's upper legs: the two concave zones of the seat's W-shaped forward portion contours the back sides of the occupant's upper legs, the very center zone of the seat's W-shaped forward portion is convex and snuggles the occupant's thighs; the seat is inclined backwardly in such a way that, when the occupant intentionally sits on the forward portion of the said seat, his buttocks, pushed by the gravity force of his body, will gradually glide backward and fit themselves into the said dedicated concave zone eventually; the left side and right side of the seat's W-shaped forward portion are convex so that they contour the outer sides of the occupant's upper legs. The seat back tilts backward to stay at an angle of 135 degrees to the seat and contours the occupant's back, wherein: The seat back's lowest portion is concave to contour the occupant's buttocks; the middle portion that is convex to contour the lumbar vertebrae; the upper portion that is concave to contour the thoracic vertebrae; the top is a headrest to provide support to the occupant's head; the left and right edges of the seat back are convex so that the occupant's back cannot bend left or right;
 2. The chair according to claim 1, in which the seat and seat back are made of low-resilient, rather non-resilient, materials to make the chair more comfortable to sit on. 